An option to show the post thumbnails is a much needed feature for this plugin. If it had this feature built in, I’d probably use this plugin over the other Related Posts plugins out there.
I took a peek into the plugin code and adding the thumbnail isn’t too difficult. All the plugin needs is a call to the featured image for the post within the plugin’s loop. Something like:
<?php if (has_post_thumbnail( $post->ID ) ): $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'thumbnail' ); echo '<img src="'.$image[0].'" alt="'.get_the_title().'" />'; endif; ?>
C’mon developer, let’s see it happen!